aboutsummaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorDaniel Stenberg <daniel@haxx.se>2010-05-21 23:04:15 +0200
committerDaniel Stenberg <daniel@haxx.se>2010-05-21 23:04:15 +0200
commit0a29e2445c8d7300b5d72e2ba05755ea1ad5b6d1 (patch)
treece7d4499663ac249650572a4c26e1ede2d6ecbdc /lib
parent700335103e039a9f56adf24cfe95fb846caebe61 (diff)
TFTP: block id wrap bug fix
In a normal expression, doing [unsigned short] + 1 will not wrap at 16 bits so the comparisons and outputs were done wrong. I added a macro do make sure it gets done right. Douglas Kilpatrick filed bug report #3004787 about it: http://curl.haxx.se/bug/view.cgi?id=3004787
Diffstat (limited to 'lib')
-rw-r--r--lib/tftp.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/lib/tftp.c b/lib/tftp.c
index 141c57570..20e5fd5da 100644
--- a/lib/tftp.c
+++ b/lib/tftp.c
@@ -572,6 +572,10 @@ static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event)
return res;
}
+/* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
+ boundary */
+#define NEXT_BLOCKNUM(x) (((x)+1)&0xffff)
+
/**********************************************************
*
* tftp_rx
@@ -590,14 +594,14 @@ static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
case TFTP_EVENT_DATA:
/* Is this the block we expect? */
rblock = getrpacketblock(&state->rpacket);
- if((state->block+1) != rblock) {
+ if(NEXT_BLOCKNUM(state->block) != rblock) {
/* No, log it, up the retry count and fail if over the limit */
infof(data,
"Received unexpected DATA packet block %d\n", rblock);
state->retries++;
if(state->retries>state->retry_max) {
failf(data, "tftp_rx: giving up waiting for block %d",
- state->block+1);
+ NEXT_BLOCKNUM(state->block));
return CURLE_TFTP_ILLEGAL;
}
}
@@ -650,7 +654,7 @@ static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event)
state->retries++;
infof(data,
"Timeout waiting for block %d ACK. Retries = %d\n",
- state->block+1, state->retries);
+ NEXT_BLOCKNUM(state->block), state->retries);
if(state->retries > state->retry_max) {
state->error = TFTP_ERR_TIMEOUT;
state->state = TFTP_STATE_FIN;
@@ -773,7 +777,7 @@ static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event)
/* Increment the retry counter and log the timeout */
state->retries++;
infof(data, "Timeout waiting for block %d ACK. "
- " Retries = %d\n", state->block+1, state->retries);
+ " Retries = %d\n", NEXT_BLOCKNUM(state->block), state->retries);
/* Decide if we've had enough */
if(state->retries > state->retry_max) {
state->error = TFTP_ERR_TIMEOUT;
@@ -1102,10 +1106,10 @@ static CURLcode tftp_receive_packet(struct connectdata *conn)
case TFTP_EVENT_DATA:
/* Don't pass to the client empty or retransmitted packets */
if(state->rbytes > 4 &&
- ((state->block+1) == getrpacketblock(&state->rpacket))) {
+ (NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
result = Curl_client_write(conn, CLIENTWRITE_BODY,
- (char *)state->rpacket.data+4,
- state->rbytes-4);
+ (char *)state->rpacket.data+4,
+ state->rbytes-4);
if(result) {
tftp_state_machine(state, TFTP_EVENT_ERROR);
return result;